Wednesday, 10 September 2008

A Big Anticlimax

Today's post is going to be my first rant. And it's going to be against the media.

This morning, at around 8.30am BST, a few thousand protons made a round trip in an 27km long tunnel. All right, as a physics student, I'm prejudiced, but it was nonetheless an achievement that took several decades of hard work, and it should soon start paying huge dividends.

I also noticed the media making a medium-level frenzy about how it might cause a micro-black hole or a strangelet, leading to the end of the world. Frankie Boyle on Mock the Week even went so far as to say the end of the universe. Despite it being a comedy show, I didn't notice a hint of humour in voice as I watched. I was also slightly appalled that he didn't care what new results the LHC will provide. This morning, a friend asked me on Facebook: 'According to the BBC, based on interviews with some of the scientists involved, "The LHC should answer one very simple question: What is mass?" Philosophically speaking, this sounds at best naïve. Can you explain?'

This chap is an intelligent man that I have quite a lot of respect for. He's part of the way through a philosophy doctorate, which, despite the mockery it sometimes gets (occasionally from me), is a very difficult subject. As far as I know, his knowledge of physics ends at either GCSE or A-level standard, but he was still capable of realising that "What is mass?" is a very stupid question, while the BBC failed to do so.

What finally made me irritated enough to write this post was an article by Gerald Warner in this morning's Telegraph. You'll find it on page 21, entitled "If you're here to read this, perhaps all is well". It's a sterling example of the press writing a scientific article without fully understanding the issue. He writes "science is entering an era of unknown risks...Where is the international jurisprudential structure to enforce responsible behaviour and consult the interests of global humanity?" He goes on to say "Decisions to proceed with certain types of research should not be taken within the magic circle of 'the academy', where the presumption is always in favour of enhancing knowledge rather than taking precautions. We need international authority, dominated by laymen but with access to expert technical opinion."

I was originally going to take up his offer and "Comment on Gerald Warner's view at telegraph.co.uk/personalview", but his article is conspicuously absent from the site. A brief search finds a blog of even greater cynicism than I would ever aspire to. I wonder where Mr Warner thinks the silicon chips in his computer were developed, or how the network that he blogs on was started?

My criticism: Let's start with Frankie. I can forgive him a little, because he is, after all, a comedian, but even comedians need to take some responsibility for the information they bring to the public's attention. There is no chance that the LHC will cause the destruction of the Universe. It wouldn't even cause the destruction of the planet. If the collisions that the LHC will create could cause such a catastrophe, it would have already happened in cosmic rays that collide with Earth and all the other bodies of the solar system every second, and have done since the Sun formed from a body of interstellar gas. I think we might have noticed the sudden loss of a planet.

All right, so the new results probably won't affect his job very much. But that's hardly a reason not to care. I suspect he would care if we landed on Mars, though I doubt that would affect him either. But then, landing on Mars would be showy. The point is that the LHC is a colossal scientific endeavour that will push back the boundaries of ignorance in same way that the telescope did for Galileo, or the electromagnet for Faraday. Even if it doesn't make a difference to him, the net effect on humanity will be huge. There is bound to be at least one person that it will affect that Frankie ought to care about.

Then there's this question "What is mass?". Some of you might think "I don't really care." I refer you the above paragraph. But this really is a stupid question. You can take either, or both (they are not mutually exclusive) views on mass that would lead you to believe, quite rightly, that this is a naïve question.

View one. We know what mass is. It is a number that we've invented, like temperature or electrical charge, that we use in our theories to predict how a body will react to certain stimuli. We define it as how much impulse we need to move a body at a certain speed, or by how much a body is gravitationally attracted to another. Asking what it is when we invented it is like a telephone engineer asking what a phone number is.

View two. The LHC will not, cannot, answer the question "What is mass?". All it can do is produce results. If these results are not in line with the predictions of our theories, then we must discard those theories. However, if they are in line, it does not make those theories "correct". It merely makes them useful. They may provide some explanation for what mass is, but accurately predicted results does not mean that their explanations are in any way true. Failure to realise this is indeed highly naïve on the part of the physicist, and only slightly less so on the part of the journalist and reader.

In face, none of the theories up for testing at the LHC is attempting to answer "What is mass?"The real question, however, is not quite so catchy on a newspaper article, and it certainly isn't simple (if you think "What is mass?" is).

Current particle physics believes that we know the fundamental particles of matter. They fall into three groups: Quarks; Leptons; gauge bosons. There are six quarks, six leptons, and five gauge bosons (that we know about, as well as their corresponding antiparticles). You can easily find a table of their properties on wikipedia or in a library book, and you will probably notice patterns. For instance, the leptons all have a charge of either -1e or 0 (where -1e is the charge of the electron, itself a lepton). All the quarks have a charge of either (+2/3)e or (-1/3)e. The gauge bosons have either +1e, -1e, or 0. However, if you look at the masses, they appear to have seemingly random numbers attached, with no obvious pattern.

Quantum theory is currently very good at predicting what a particle will do, given its properties. Some theories even managed to predict the existence of particles with certain properties, such as antimatter and strange quarks. But it hasn't, yet, been very good at predicting what masses the new particles will have. And it is the theories that try and do this that the LHC will test.

All right. On to Gerald Warner.

Firstly, this morning's test was a trial run. The protons made a round circuit, and then stopped. No collisions occurred. So even if his fears had any foundation, he loses respect for sheer ignorance. Forgivable in a "layman" as he calls them. Not in a reporter who is supposed to inform the public.

Secondly, he goes on to say that "Dissident scientists are concerned about a number of possible hazards: the creation of black holes, the generation of "strangelets", monopoles, black energy, vacuum energy - all mysterious to the layman." Clearly, then, he is a layman. A monopole (by which I assume he means magnetic monopole - I cannot believe him to be so stupid as to think an electric monopole any kind of danger) is no danger whatsoever, though it would certainly be interesting. I have never heard of "black energy", though he may possibly mean dark energy or dark matter. Both, if they exist, are supposed to be massive and very weakly interacting, which means that there is so little they can do that we will only notice them by the absence of other particles. Vacuum energy is the energy of free space. Are you worried by space between you and your computer screen? Hardly. And anyway, who are these dissident scientists? What peer-reviewed papers have they published on the subject? What research do they have to back up their theories? Are they widely respected as authorities on these subjects? No. This is why they are dissidents.

Black holes and strangelets, however, do deserve some explanation. A black hole is formed when matter is clumped together past a certain critical density. This doesn't happen often, because matter repels matter at short distances, via something called the exchange principle. Only the collapse of massive stars, hundreds of times larger than the sun, is considered to be enough. However, it is just possible that the LHC will be able to concentrate matter enough to reach this critical density.

Strangelets are clumps of quarks consisting of roughly equal numbers of up, down and strange quarks. They are completely hypothetical; unlike black holes, we don't even have circumstantial evidence for them. The worry is that, on contact, they turn normal matter into strangelets, and could lead to a chain reaction that would convert the entire planet.

Why I'm not worried about black holes consuming the Earth: If a black hole was to be created, it is predicted that it would decay rapidly by a process known as Hawking radiation. It would be lucky to last as long as a second. Warner's response to this is that Hawking radiation is no more than a theory. He is correct; we haven't found any handy black holes to test it on, which is something the LHC should provide. However, Hawking radiation is a widely accepted theory that has no theoretical weaknesses. I'm prepared to bet on it being fairly accurate. However, even if it turns out otherwise, we should still be able to capture our baby black hole with an electromagnetic field (black holes can carry electric charge) and keep it safely from harm. Even failing that, it should still take several centuries before it has any noticeable affect on us. Plenty of time to find another planet to live.

As for strangelets, I'm betting we won't find any. The aforementioned cosmic rays should have consumed most of the solar system if the energies we're dealing with had even the faintest chance of one cropping up. Furthermore, the idea that they convert normal matter is also an untested theory, and one with far less going for it than Hawking radiation.

You might think I'm taking an unnecessary and irresponsible risk. It is a risk, certainly, but not an unnecessary or irresponsible one. It is one that we need to take in the interests of science and the advancement of mankind, just as we took when we exploded the first atomic bomb, drove the first car at sixty miles an hour (it was thought that the driver would suffocate), and broke the speed of sound. Warner claims that we are entering "an era of unknown scientific risks". How insightful! All risks arise from the unknown, whether it be if the stock market will go up or down, or if you missed seeing a car when crossing the street. Risks are to be managed, not avoided. What Warner is advocating, ironically enough, is to procrastinate the inevitable.

Finally, I want to heap scorn on this idea of "an international authority, dominated by laymen but with access to expert technical opinion" that he thinks should decide on the avenues of research, rather than "the magic circle of 'the academy', where the presumption is always in favour of enhancing knowledge rather than taking precautions." These quotes again show Mr Warner's colossal ignorance of the subject.

Scientists bring more to the table than just sheer knowledge. They bring a scientific approach. Put laymen in charge of all scientific research decisions, and one of two things will happen: Either, our laymen will become technically minded scientists in their own right; or, more likely, the will have no idea what is good research and what is not, and will make decisions based on faulty judgement and information. Expert technical opinion is of no use if you do not know what it looks like, so our laymen could be bombarded by bad science such as creationism, and end up making bad decisions. In any case, "laymen" have quite a lot of say in how research is done: laymen like publicly elected politicians who control research budgets, grants from private companies and foundations, and, possibly the biggest contributor, the military. There is no "magic circle of 'the academy'".

Furthermore, what reason does Mr Warner have for thinking that "the presumption is always in favour of enhancing knowledge rather than taking precautions." Scientists don't want the world to end any more than he does, and considerably less than some. Anyone unbalanced enough to want to herald the Apocalypse is unlikely to have the intellect work in the field of science. Scientists take every precaution, because they're often the ones at the centre of the blast zone. Failures like Chernobyl, Three Mile Island, and other disasters occurred, not because of bad science, but because of poor engineering, management, or interference from politicians. Everything that happened, happened in exact accordance with theory.

I want to end by confessing that scientists ought to take some responsibility for outrages like Frankie Boyle's comments, the BBC's inaccurate reporting, and Mr Warner's ignorance. Scientists are not often expected to explain their theories to non-scientists or non-engineers, and I have noticed that scientists (particularly physicists) are often very poor at communicating their theories to the rest of the world. But the fact is that many people simply aren't interested, don't understand, or worst of all, think they understand but don't. Scientists have a responsibility to change that, and "laymen" have a responsibility to as well.

3 comments:

Brunellus said...
This comment has been removed by the author.
Brunellus said...

The instrumentalist doth protest too much, methinks!

(i) If all we mean by ‘mass’ is a variable occurring in certain equations that happen to be predictively useful, why do we call it ‘mass’ rather than, say, ‘energy’ or ‘force’?

(ii) Scientists usually want to provide explanations for things. If certain equations happen to be predictively useful, what is the explanation of their success?

Res said...

(i) Habit or history, as far as I know.

(ii) I honestly have no idea. I suppose you might claim that they are in some way closer to the true law of nature, but there's really no way of measuring that. Physicists do stick to certain rules when constructing theories, such as logical consistency, and the principle of relativity, but even within their scope, there's plenty of possibility.